Smart Resistor: Stabilization of DC Microgrids Containing Constant Power Loads Using High-Bandwidth Power Converters and Energy Storage

Abstract

Power electronic converters and electric motor drives have found increased application in dc microgrids, electric automobiles, and ships. Such converters when driving loads in a regulated fashion act as constant power loads (CPLs). These CPLs can cause destabilizing effects on the grid because of their negative incremental impedance. This paper proposes a method to dynamically stabilize CPLs at the point of load by making them behave as adaptive Smart Resistors by using high-bandwidth power converters and energy storage units. These Smart Resistors can work with smart sources to realize ultimate intelligent power networks. The control strategies needed to achieve the concept, including voltage and current trajectory control principles, are analyzed and validated with a hardware test setup.